IR spectroscopy measurements may be useful for a variety of purposes including aerospace, automotive and industrial applications, as well as biological and bio-medical applications. For example, infrared (IR) radiation is readily absorbed by organic materials in association with relative motions (vibrations) of atoms such as carbon, hydrogen, oxygen and nitrogen. As such, IR spectroscopy measurements may indicate a condition of a wide variety or organic materials.
For example, organic polymer materials such as resin-fiber composites or adhesives may change over time due to a variety of reasons including heat exposure. Chemical changes to a polymer containing structure may affect the desired properties of the polymer containing structure including structural integrity such as strength of a composite or the adhesive properties of an adhesive.
One problem with prior art approaches to making IR Spectroscopy measurements of polymer containing materials is that a signal-to-noise ratio may be insufficient to determine relative changes in chemistry of the material. For example, prior art Fiber Optic Probes have failed to address the problem of Fresnel reflections from a surface of a sample which may obscure molecular absorption and/or fluorescence spectral data that may be present in the scattered light signal from within a sample.
In addition, prior art devices and methods for making IR Spectroscopy measurements of polymer containing materials have the drawback that they may only be able to measure the outer surface of the material. For example, prior art IR Spectroscopy approaches typically require destruction of a material in an ex-situ setting.
Accordingly, there is a need for an improved spectroscopy non-destructive testing device and method for using the same to non-destructively determine a condition of organic containing materials, including fiber reinforced composite materials, over small sampling areas and/or in hard-to-access configurations with a suitable signal-to-noise ratio.